Security devices, such as padlocks and other types of conventional locks, are used, for example, to prevent access to a room, building, enclosure, container, or piece of equipment. Exemplary padlocks include those opened by a key and those opened by manipulation of lock components in accordance with an authorized combination. In a conventional padlock, a shackle is secured within a lock body by one or more internal locking members that are received in corresponding notches in the shackle to prevent axial withdrawal of the shackle from the lock body.